Posted
by
samzenpuson Wednesday August 18, 2010 @07:59PM
from the level-1-random-encounter dept.

nibbles2004 writes "An article in the Guardian newspaper shows how parasitic fungi evolved the ability to control ants they infect, ultimately leading the ant to its death. The fungus controls the ant's movements to a suitable leaf and causes the ant to grip onto the leaf's central stem, allowing the fungus to spore, which will allow more ants to become infected."

Been there, done that, plants fart and the world commits suicide. Now if only Shiamalan would actually die in real life instead of his cameo appearances in his movies, then mistakes like "The Last Air Bender" could be avoided.

But isn't this same fungus found in some humans, too? It doesn't cause them to climb trees, but it does tend to make them more aggressive, paranoid, and less able to deal with authority IIRC. I thought there was a/. story about it, and how the the higher a country's proportion of infection was, the more likely they were to have a better Soccer team...

"Toxoplasmosis is a parasitic disease caused by the protozoan Toxoplasma gondii.[1] The parasite infects most genera of warm-blooded animals, including humans, but the primary host is the felid (cat) family. Animals are infected by eating infected meat, by ingestion of feces of a cat that has itself recently been infected, or by transmission from mother to fetus. Although cats are often blamed for spreading toxoplasmosis, contact with raw meat is

I think the connection to cats the op was attempting to make was where it altered the behavior in rats and they didn't fear cat urine anymore, not necessarily how it was spread. Of course cats eating rats is a source of raw meat so it does sort of control the rats.

You are both right and informative, it just seems that you are both talking about separate aspects pertaining to the same thing..

Its interesting because my nephew was diagnosed with fungal meningitis about 18 months ago. He was otherwise healthy, not immune deficient. He is 15, does well at school and plays sport. A scientist who works in the field told me that treatment for fungal infections is much harder than for bacteria because more things which kill fungus, also kill us.

So far I haven't seen any fungus induced behavior change in my nephew, apart from the normal effects of a brain infection.

Ant brains are very tiny, and the control and regulation mechanisms in them are simple. Human brains are immense, complex, and very hard to control. A fungus could make it fuzzy or twitchy, but to actually alter a behavior to its own ends is unlikely times ten to the fifteenth power.

There are about 1.5 million kinds of fungi, many of which will infect humans (basically move in and treat us like a tree root). They can live in us, but they don't particularly get anything out of us evolutionarily until we die and they can become spores as our corpses dessicate. Which they're content to wait for, as long as we haven't developed anything to kill them outright that might result in superiority of mutations that (a) don't die from our medicine and (b) make us reject medicine entirely. (Maybe scientologists and christian fundamentalists have a brain fungus. It would explain a lot.)

The really interesting thing is that while the spores are contagious (it's how we get infected), the living form of the fungi are generally not. So your nephew most likely can't infect anyone by contact.

The larger world defeats this by not drinking the water other people are washing their pustules in.

And come to think of it, pretty much any skin disease that makes you scratch at it is trying to get you to spread it to more skin, so that's a behavioral modification, albeit not a brain-control mechanism per se.

Watch the Planet Earth series. There are hundreds of strains of fungi like these, that all infect various insects. Moths, grasshoppers, praying mantises... they're all very, very species specific. So much so that they actually act as a natural balance so that no one species crowds out others because if they get too populous they end up being more vulnerable to the spores because of the denser population.

Tell me about it. These are supposed to be so called nerds here. Slashdot users should switch on the discovery channel every now and again, and then realise that this is not news, it's olds.

Then there's the worse insult. What self respecting nerd hasn't seen Planet Earth in HD. Man there were some awesome scenes in that. The fungus growing out of the ants head in timelapse was just one of many.

Fungi are very interesting in more ways than one.. In addition to these mind controlling abilities, it seems they can use gamma radiation in similar ways than plants do photosynthesis with light. http://en.wikipedia.org/wiki/Radiotrophic_fungus

Now, as gamma radiation can penetrate very deep in all kinds of material, what organism could be better suited for outer space and life inside asteroids than fungi? Add to that all those problems with classification of them as either animals or plants.. Maybe fungi is

This sounds like a wonderful new weapon to develop. Human Zombies that explode spreading their Zombiefing spores. That should solve our terrorist problems rather quickly. Guess I need to stock up on anti-fungi's down in the bunker.

- organisms that survived and procreated did something successful, and

- behavior is inherited.

This sounds to me like the ant climbs because the fungus is in its head and its trying to escape it by going higher. There's a similar organism reproduction cycle with ants where the ant goes to the top of grass, and the ant is said to be controlled to do that so it is easy prey for a bird where the organism continues the cycle in the intestines.

The way this should be viewed is that parasites that attacked certain areas of their host that resulted in host behavior that was most successful for the parasite to move to the next stage of growth survived, and others who didn't are not here. Neither "controlled" the host, it is blind evolutionary luck.

Similar can be said about organisms that release toxins that force a flushing action for their onward journey. Did they "control" the host to develop diarrhea? No, those that perform actions that allow for survival and procreation survived and procreated. Unfortunately for both ants and humans, with devastating, but thoughtless, effectiveness.

Here's another one [slashdot.org] that was mentioned on slashdot, although it is also a worm inside of grasshoppers that convinces the insect to move towards water. Another one eats the brain [slashdot.org] even if it doesn't control it. Or wasps that control cockroaches [slashdot.org] with toxins injected into the brain.

I was certain I had seen this story on Slashdot before, but I can't find it now......but it's mentioned in the comments [slashdot.org].

BBC Planet Earth shows the cordyceps fungus attacking some Bullet Ants in South America. It is incredible camera work showing the ant being forced to climb, and later a time lapse of the fruit body erupting from the ant's body. It is short but very well filmed, as is the case for the entire series.

HIGHLY recommend watching this if you have any interest in nature.

The cordyceps section is around 28 minutes into the "Jungle" episode. You won't be dissapointed.

Actually I searched youtube and found an excert of this episide including the cordyceps on the ants. The cordyceps part starts about 4 minutes into this video:

http://www.youtube.com/watch?v=_qabQZQQrGk

I still recommend getting the blue-ray or at least dvd of this series, can't say enough good things about it in general.

By the way having read the article better, it seems to imply the fungus actually is taking "over its brain and muscles" then killing the creature. In reality it is likely the fungus is making the ant feel more comfortable in this area or changing the way its pheremones tell it to go.

The incredible thing though, is according to wikipedia: "The changes in the behavior of the infected ants are very specific and tuned for the benefit of the fungus. The ants generally clamp to a leaf's vein about 25 cm above the ground, on the northern side of the plant, in an environment with 94-95% humidity and temperatures between 20 -30 degrees C. "

That is pretty damn specific, amazing so simple an organism can induce behavior that complex in an ant.

It doesn't have to induce behavior that complex -- it just has to inhibit or stimulate responses already genetically programmed into the ant.

Its not a safe assumption that anything about the fungus is directly causing those behaviors -- there's a lot of fungus in the world, and there's a lot of species that fungus may grow on. All you need is one combination to be beneficial to the fungus, and it'll spread.

The fungus evolved to survive in that climatic condition, as well as when the ant performs the necessary behavior.

Future mutations may allow the ant to clamp 20 cm up the stalk, or in a 32 C environment. Or future mutations of the ants may delete a key signalling chemical the fungus was using, and wipe it out from lack of victims.

The way you describe it, I almost sort of see an arduino controlling a few servo motors and a smell sensor, and the fungus is shorting the smell sensor's output to 1 or 0 to manipulate the ant's programming.

That is pretty damn specific, amazing so simple an organism can induce behavior that complex in an ant.

Not really - that's how evolution works. Those conditions are almost certainly what is optimal for reproduction of the fungus. Fungii that made the ants go 50cm high or on the southern side of the plant etc. wouldn't have had as successful a rate of reproduction and would rapidly have lost evolutionary space to the "better" fungii. Millions of years of random trial and error provide lots of opportunity t

That is pretty damn specific, amazing so simple an organism can induce behavior that complex in an ant

What you miss is that the programming which means the complexity of all organisms is contained within each individual cell. From a computer standpoint one would have to view all life forms as simply a network of computers where for any given network (individual) all computers (cells) have the same programming.

It is just that some of these computers (cells) perform different functions and I guess that wou

They mention that the other ants in the colony can usually detect when one of the ants gets infected, and actually move her as far from the colony as possible if they can before she goes all Zahn on them.

I remember stumbling upon it when I was watching videos about other parasites. Some good stuff out there... There are also parasites that can do

An article in the Guardian newspaper shows how parasitic fungi evolved the ability to control ants they infect [emphasis added]

No... not really. If you RTFA, it gives a nice outline of what we have known for many years about the fungus controlling the ants, and it mentions the new fact: That evidence of the behavior is found in 48 million-year-old fossilized plants. Nowhere does the article even hint that we have even a remote understanding of the "how".

Allow me to quote the end of the article:

He added: "Of all the parasitic organisms, only a few have evolved this trick of manipulating their host's behaviour.

Why go to the bother? Why are there not more of them?"

Scientists are not clear how the fungus controls the ants it infects, but know that the parasite releases alkaloid chemicals into the insect as it consumes it from the inside.

There's an even gorier and specialized example, the emerald cockroach wasp, which will damage a cockroach's brain to remove all survival instincts so it allows itself to be infected and eaten alive from the inside out: http://en.wikipedia.org/wiki/Emerald_cockroach_wasp [wikipedia.org]

Without looking at the link, as I recall, it stings the cockroach at the base of its brainstem, and somehow its toxin destroys the cockroach's free will. It turns into a zombie, and the wasp can then just pull on its antennae like a leash and walk it to the burrow. There, it gets an egg laid on it, and the wasp administers another sting, that permanently cripples the cockroach. The cockroach remains alive though, to await its fate of being eaten alive.

The basics: Barnacle attaches itself to crab. Weaves tendrils throughout crabs central nervous system to take control of the crab and also leach neutrients from it. The crab stops growing and molting at that part. It will not engage in normal behavior like regrowing lost limbs. Anything behavior that does not serve the parasite is suppressed If the c

If both a fungus and a flatworm can make an ant climb onto the right leaf, I wonder if there's some easy way to trigger an algorithm in the ant's brain that homes them to the right spot? Oh, and if I recall correctly, there's a bee or wasp that can sting an ant's head, injecting its venom into the correct nerve ar

I'm a fungus afficionado, if there is such a thing, and here I was all excited that they'd actually made some progress explaining how the fungus causes the ants to carry out such very specific behaviors. And the summary made it sound like that... But it basically boiled down to a sentence or two at the end of the article saying "We think the fungus uses some kind of chemicals on the ants. We don't really know." What a bunch of bullshit.

I'm a fungus aficionado, if there is such a thing, and here I was all excited that they'd actually made some progress explaining how the fungus causes the ants to carry out such very specific behaviors. And the summary made it sound like that... But it basically boiled down to a sentence or two at the end of the article saying "We think the fungus uses some kind of chemicals on the ants. We don't really know." What a bunch of bullshit.

"The fungus controls the ants movements to a suitable leaf and causes the ant to grip onto the leaf's central stem, allowing the fungus to spore which will allow more ants to become infected."

Sounds like modern, social-networking.

I propose that, in the future, Facebook users are referred to as "Zombie Ants!" (must include the exclamation) and Facebook be referred to as "Killer FungusBook" (may be substituted with "Necrotizing FasciitisBook" when used in academic circles).

That's the thing about Sci-fi. Someone dreams it up, then it becomes even scarier when it is found to exist in real life. (or something close to it). I know, Halo isn't the first to explore the motiff, but I have to say it:

I'd love to change the world, but I'm reading 10 year old second-hand knowledge on slashdot. Really, if you're reading slashdot and didn't have this knowledge fully integrated into your consciousness...head on over to digg.

Equally fascinating and cool... a wasp that paralyzes a caterpillar only to lay larvae in it. The larvae attack the brain and control it forcing the caterpillar to protect them as they grow and eventually cocoon itself in a safe location so they can consume the host's body inside out.

Consider any viral infection in humans, a virus hardly even being an organism, that cause behavioral changes and forces the human to seek out large groups of fellow individuals (hospitals), only to involuntarily spray them with bodily fluids (vomiting, diarrhea).

And it isn't true that there aren't more of the fungus, like the article claims. Planet Eart clearly states that there are thousands. And I believe that an ant has a fairly simple cortex, allowing simple chemical influences to make it go up, left, r

When I first learned about mud dauber wasps and how they fed their young I said "Holy crap, that's where they got the idea for Alien." Similarly I realized the inspiration for the Blob when I learned of ameobae. When I read about zombie ants and saw the video of the fruiting bodies I couldn't believe nobody used this as a movie monster threat yet. Person gets infected with death fungus, behavior becomes erratic and violent until he dies. Once the body collapses the fruiting bodies burst forth and anyone who

Apparently, toxoplasmosis [wikipedia.org] causes infected rodents to *stop fearing* and avoiding the smell of cat urine, causing the rodents to be more likely to be eaten by cats, completing the cycle by getting the toxoplasma back into cats where they can reproduce. (Rats eat cat turds in the other side of the cycle).Sorry if you're eating while reading this!Toxoplasmosis is the reason why pregnant women should not clean out cat litter boxes. It can cause a serious infection in the unborn or newborn baby.Also, it may cause infected humans to engage in more risky behavior, like driving behavior that leads to increased car accidents. (Or even schizophrenia?)Heard about it on NPR's Radiolab. Cool show. Get the podcasts.